Radiomitigation
The tragic nuclear power plant accidents in Fukushima, Japan caused severe leaks of radioactive Iodine-131 and Cesium-137 and a subsequent widespread exposure scare of radiation. In addition, the global use and storage of radioactivity is increasing rapidly. Millions of radioactive sealed sources are used around the world for legitimate and beneficial commercial applications such as cancer treatment, food and blood sterilization, oil exploration, remote electricity generation, radiography, and scientific research. These applications use isotopes such as Cesium-137, Cobalt-60, Strontium-90, Americium-241, Iridium-192, Plutonium-238, Plutonium-239, Curium-244, Radium-226, and Californium-252. Many of these radiological sources at sites around the world are no longer needed and have been abandoned or orphaned; others are poorly guarded, making the risk of theft or sabotage significant. Currently, there are tens of thousands of civilian locations worldwide with radioactive material, about 5,000 of which contain sources of 1,000 curies or greater (Office of Global Threat Reduction (NA-21), GTRI Strategic Plan, release date January 2007. 955 L'Enfant Plaza, Washington, D.C. 20585. Iliopulos, Ioanna et al. The Office of Global Threat Reduction: reducing the global threat from radiological dispersal devices. 2007. JNMM Volume 35 Issue 3 PP 36-40). Beyond the public safety concerns are the clinical implications of radiation use.
Outside the radiation therapy clinic there is also significant relevance to identifying and characterizing novel compounds that protect cells from radiation induced cell death.
Fundamental to radiation exposure and injury is DNA strand breaks, resulting in genetic instability and DNA deletions which are involved in cell death, cellular dysfunction, as well as long-term consequences such as birth defects and cancer.
Discovery of compounds that are capable of mitigating the process of normal tissue damage from radiation during radiotherapy, accidents, or terrorist attacks is of importance. Most currently available treatments for radiation exposure are free radical scavengers that reduce initial radiation-induced DNA damage and work best if added just before or at the time of irradiation. Because of this, these compounds are not practical countermeasures in a radiation incident. In that case, the search for radiomitigators—agents with robust, prolonged efficacy, broad specificity, and minimal toxicity that could protect a large population in the event of a radiological emergency is of importance.